Electric safety device for the flowing out of excess voltage.



G. GILES.

ELECTRIC SAFETY DEVICE EOE THE ELCWINC OUT 0E EXCESS VOLTAGE.

APPLICATION FILED AUG. l2. 190B.

1,C40,927, Patented Oct. 8, 1912.

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UNITED STATES PATENT oEErcE.

GEORGES GILES, OF FRIBOURG, SWITZERLAND.

ELECTRIC SAFETY DEVICE FOR THE FLOWING OUT OF EXCESS VOLTAGE.

Specication of Letters Patent.

Patented Oct. 8, 1912.

Application filed August 12, 1908. Serial No. 448,095.

To all whom it may concern:

Be it known that I, GEORGES GILEs, engineer, citizen of the United States, residing at Fribourg, in the Canton of Fribourg and Confederation of Switzerland, have invented certain new and useful Improvements in tric safety device for the flowing out of eX- =cess voltage of which a constructional form is shown partly in section in Figure Il of the annexed drawing. Fig. Q. is a schematic view showing the operation of the apparatus.

The apparatus shown in Fig. 1 comprises two electrodes el, e2, between which is provided a spark gap the length of which may be adjusted by screwing' or unscrewing aY screw carrying the electrode c1 and which can be maintained inv any desired position by means of a locknut. The electrode e2 is connected with one end of a high resistance R of f. i. 5 to 10000 ohms, in form of a tube surrounding an insulating core.

c3, e4 are metallic disks with sharp edges forming a series of electrodes between which spark gaps are provided. Said disksV are placed on a metallic rod t from which they are insulated by a tube t1 of insulating material, f. i. of micanite, and by rings r ot' insulating material havin@ flanges by which the disks are also insulated from each other. The electrodes e3, c* thus at the same time are constituting armatures of little condensers from which t-he second armature is constituted by the metallic rod t. The first electrode e3 of the series is electrically connected wit-h the resistance R and the last electrode of the series is in contact with the rod t. The apparatus'being connected as shown in Fig, l with a line l on one side, and with the earth on the other side, the electrode e1 is at the potential of the line and the electrode c2, as Well as all the electrodes e3, et. of the series, are maintained at the potential of the earth by medium of the little condensers. The spark gap between the electrodes .61, e2 is. adjusted so that a spark springsbetween the electrodes as soon as the voltage inthe line Z attains the value from which it is desired to obtain the flowing out of excess voltage. It being admitted that this voltage is of 10,000 volts, and that it has been attained, a spark springs between c1 which is at the potential 10,000 and e2 which is at the potential 0. The current thus formed will be very weak because it has to flow through the condensers and the drop of voltage between el and c2 will be approximatively o-f 500 volts. The drop of voltage in the resistance R will equally be weak according to the weakness of the current and the electrode c3 will therefore be charged approxinlatively to the potential The electrode c* beingalways to the potential 0, a spark springs between c3 and c* and the electrode e4r is charged to the potent-ial Sparks will similarly spring between et' and e5, e and es, etc., each time with a drop of voltage of 500 volts, a cascade starting of the sparks between the disks being thus obtained. The number of the disks is taken such that when the sparks have thus been started until the last but one electrode, a sufficient difference of potential, of 2 to 3000 voltsl approximatively, is remaining for starting a spark between the two last electrodes. When all sparks are started, the flowing out of the excess voltage is produced directly through c1, c2, R and the series of electrodes, the last of which is metallically connected with the earth.

It has been foun`d that the apparatus thu constitute-d has the property of permitting the flow of electricity only when the voltage exceeds the value for which the spark gap between cl and c2 has been adjusted. As soon as the voltage is becoming inferior to that value, all sparks are ceasing by themselves without any blow out of the same. It has further been found that owing to the presence of the high resistance R any production of high frequency currents in the apparatus itself is avoided. The said-resistance R is chosen according to the relation where C and L-designate the capacity and the self-induction of the apparatus of the protected circuit. It was found that with a. resistance larger than 5,000 ohms theI production of currents with high frequency was practically prevented. Agt last it was found that when several apparatus formed y as described above are placed in parallel as quency R of say 10,000 ohms in one apparatus is producing no currents of high frequency, ten

apparatus, each with a resistance of 10,000

ohms and placed in parallel Will also produce no currents ofl high frequency. However the resistance equivalent to the ten resistances of 10,000 ohms placed in parallel is only 1000 ohms and currents of high freare produced when. only one apparatus with a resistance, of 1000 ohms is employed. n i

rlFhe apparatus described above is particularly suitable for obtaining theowing out of excess voltage produced by resonance phenomena of low-r frequency in cable het` Works, For high frequency,A phenomena produced in aerial lin by atmospheric inuences, the' employment of eondeisers is always the best system., (Claims:

l, 1. An apparatus of the character described having a series of annular electrodes; a series of rings of insulation formed with outwardly-extending flanges which separate said electrodes from one another; and a me,

Loewe? tallic rod which passes through said rings of insulation and is separated from all except one of said electrodes by said rings, whereby ,starting condensers are formed to which said rod is common as the second armature thereof; the excepted electrode being directly conneet/ed to said' rod.N

2. An apparatus of the 'character described having a series of annular electrodes; a series of rings of insulation formed with outwardly-extending anges which separate saidelectrodes from one another; a metallic rod. which passes through said rings of insulat-ion and is separated from all `except one of said electrodes by said rings, whereby starting condensers are formed to which said rod is common as the second armature thereof, the excepted electrode being directly connected to said rod; a line-Wire electrode which is separated from said metallic rod by a main spark-gap;v and an ohmic resista-nce arranged in series with said. rod.

ln testimonywhereof l have aiiixed my signature in presence of tvvo Witnesses.

GEORGES GHJES.

Witnesses: v

1R. nr. WUns'raMnEncrn, y FRANCIS B. KEENE. 

